The data on this page is more precise and in some cases more up-to-date than the data engraved on the wooden tiles. But as always, never believe one source if the number really matters. Density, melting point and boiling point data is particularly variable and uncertain.

Special notes for this element from IUPAC publication:Geological specimens are known in which the element has an isotopic composition outside the limits for normal material. The difference between the atomic weight of the element in such specimens and that given in the Table may exceed the stated uncertainty.

Range in isotopic composition of normal terrestrial material prevents a more precise Ar(E) being given; the tabulated Ar(E) value should be applicable to any normal material.